Less than a week after asserting that race was the driver "for some" opposition to President Barack Obama's policies, Attorney General Eric Holder said Americans need to be "color brave" because the nation is "not yet colorblind."

Speaking to an audience as part of Howard University's celebration of the 50th anniversary of the Civil Rights Act, Holder revisited the achievements of the civil rights movement before asserting that "as it stands, our society is not yet colorblind; nor should it be, given the disparities that still afflict and divide us. We must be color brave."

The attorney general told students on Tuesday that "significant challenges remain" for the nation, which he said was "founded on equality but built by those in chains."

The current controversy surrounding Holder and race was triggered during a Sunday interview on ABC News' "This Week" program.

In response to a question from justice correspondent Pierre Thomas, Holder contended that Obama "has been treated different than others" and that race was a "driver for some people" behind their objection to the president's policies.

"For whatever reason, Republicans decided early on that this was a president that they simply were not going to cooperate" with, he added.

During the interview from London, Holder also said he had no regrets and would "not walk away" from a Feb. 18, 2009, speech he delivered in which he said America was "a nation of cowards" when it comes to discussions of race.

"Though this nation has proudly thought of itself as an ethnic melting pot, in things racial we have always been and continue to be, in too many ways, essentially a nation of cowards," Holder said in the speech to Justice Department staffers while marking African American History Month.

Holder expressed to the Howard students his belief that the national dialogue on race would be "very different" if the conditions of "lower social and economic mobility" and "unequal justice and unfair outcomes" were "felt so acutely by the majority of Americans."

Less than a week after asserting that race was the driver "for some" opposition to President Barack Obama's policies, Attorney General Eric Holder said Americans need to be "color brave" because the nation is "not yet colorblind."